Wróbel Borys, Wegrzyn Grzegorz
Institute of Oceanology, Polish Academy of Sciences, Gdynia.
Virus Genes. 2002 Mar;24(2):163-71. doi: 10.1023/a:1014576701341.
Comparison of the putative iteron-binding proteins of lambdoid phages allows us to propose that in the case of lambdoid replication modules, the units on which natural selection acts do not coincide with the open reading frames. Rather, the first replication gene is split into two segments, and its 3' part (corresponding to the C-terminal domain of the iteron-binding protein) forms one unit with the second gene. We also propose from the phylogenetic analysis of phage-encoded homologs of E. coli DnaB and DnaC, that the recombination with the host sequences is not frequent. Accessory ATP-ases for helicase loading (E. coli DnaC homologs) may not be universal replication proteins. Our analysis may suggest that the bacterial helicase loaders might be of phage origin. The comparison of DnaC homologs of enterobacteria and enterobacterial phages supports the experimental data on residues important in interaction with DnaB. We propose that construction of plasmids carrying the replication origins of lambdoid prophages could be useful not only in further research on DNA replication but also on the role of these prophages in shuttling genes for bacterial virulence. The phage replication sequences could be also useful for identification of clinical enterobacterial isolates.
对类λ噬菌体假定的迭代子结合蛋白进行比较，使我们能够提出，对于类λ复制模块而言，自然选择作用的单位与开放阅读框并不一致。相反，第一个复制基因被分成两个片段，其3'部分（对应于迭代子结合蛋白的C端结构域）与第二个基因形成一个单位。我们还从噬菌体编码的大肠杆菌DnaB和DnaC同源物的系统发育分析中提出，与宿主序列的重组并不频繁。用于解旋酶加载的辅助ATP酶（大肠杆菌DnaC同源物）可能不是通用的复制蛋白。我们的分析可能表明，细菌解旋酶加载器可能起源于噬菌体。对肠杆菌和肠杆菌噬菌体的DnaC同源物进行比较，支持了关于与DnaB相互作用中重要残基的实验数据。我们提出，构建携带类λ原噬菌体复制起点的质粒不仅有助于进一步研究DNA复制，还有助于研究这些原噬菌体在穿梭细菌毒力基因中的作用。噬菌体复制序列也可用于鉴定临床肠杆菌分离株。
